<div>
  Use the servlet container to authenticate users, as per defined by the servlet
  spec. This is historically what Jenkins has been doing up to 1.163. It is
  useful mainly for the following situations:

  <ol>
    <li>
      You've been using Jenkins before 1.164 and would like to keep its
      behavior.
    </li>
    <li>
      You've already configured your container with the right security realm and
      prefer Jenkins to just use it. (Sometimes the container offers better
      documentation or custom implementations to connect to a specific user
      realm.)
    </li>
  </ol>
</div>
